The 31-year-old was diagnosed with testicular cancer in May this year, but after undergoing a course of treatment and following his latest medical check-up, doctors have now given him the green light to join up with his team-mates again.

"We're all delighted about Marco's news," said Frankfurt head coach Niko Kovac. "He came here to tell us himself. It's wonderful. He has the doctors' permission to pursue his career once more and will now start with a program of rehabilitation. To start with, he needs to work on his fitness. But he'd like to be as close to the team as possible, and wants to make the trip to Hamburg with us."

A short while ago there were signs that Russ' spell on the sidelines was coming to an end. He revealed that, after undergoing a course of chemotherapy, his health was improving and that he was targeting a return to full training in January. In a show of solidarity, Frankfurt extended Russ' contract until 2019.